Here we studied a large population of subjects to determine the frequency of abnormal Th2 skewing of CD4+ T cells in patients with coccidioidomycosis and to identify underlying genetic mechanisms supporting this phenotype.<h4>Methods</h4>We collected peripheral blood mononuclear cells from 204 patients with coccidioidomycosis, including 96 patients with disseminated disease. This evidence concerns the gene CD4 and coccidioidomycosis.